Inverter power fridge while driving? Intermittent loss of power w/ genset.

[Newcsn]

Last fall when we were running up & down the road, I seem to recall that the engine/alternator would power the fridge - via the inverter - while driving. Am I recalling that correctly?

Today, while driving, we had to run the generator in order to power the fridge.

Also, we’re parked tonight & running the generator and the 110 system intermittently has lost power a couple times (TV & clocks go off and then come back on). 

Do I need to reset the inverter?

Thanks in advance for your feedback!

[Gary_Curtis]

I have found that the 110 system provides intermittent power when the generator is maxed out. I had three air conditioners and the fridge going at the same time and was trying to use a power tool plugged into one of the receptacles in the storage bay.  I turned off the Air conditioning units and 110 power was stable at the receptacle. 

I never did the math but my generator provides 10KW.  An air conditioner consumes about 1000 watts. A full size Refrigerator about 1000 watts. My power tool (10 in table saw) 1500W. When you add all that up it is only 5.5 KW but my generator may not be putting out 10KW. I have no way to actually measure its output.

 

[jacwjames]

Is the refrigerator original to the coach??  Was it upgraded from a Norcold?

Do you have two outlets behind the fridge.  In my case I have two, one powered through the inverter and the other off shore power and/or generator.  Is there a chance it might be plugged into the wrong one if you have two outlets.   My refrigerator is plugged into the inverter circuit and will fun using the alternator while driving down the road.  I seldom run the generator.

Will the refrigerator run while plugged into shore power???

Is your refrigerator powered with an outlet connected through the inverter?? 

 

FWIW, I have a 7.5KW Onan generator.  It recommends running it at least once per year at full load to clean out the spark arrestor of any soot build up.  So when I do this I run both my AC's, water heater, small toaster oven and possibly a small cube heater to get the amp load up to +60 amps.  So your generator should be more then capable of running  the AC's and refrigerator without being overloaded as you probably have a minimum of a 10K generator.

 

[TomV48]

On some coaches the inverter powers the gas / elec frig.   Ours has two outlets in the back.  One powers the frig from only gen or shore hookup. The other is from the inverter and is intended to power the ice maker by inverter when off hookup/gen and frig on gas.

One trip (season) our gas was dead and while waiting for the new frig, (7+ mo back order) I ran the frig off inverter, but that is not viable long term so we had to find hook ups at every camp.

In rough terms, the four door Norcold pulls 4 amps of 120 v ac.    But on the inverter, with average battery voltage above 13 vdc from our lifepo's the inverter was pulling an "extra" 41 amps.   That worked ok when the engine was running because our DC TO DC charger gave us 40 amps, but off hookup with frig on inv, and our normal TV and Dish etc,. one overnight was barely sustainable even with our 600 amp battery bank.     

Makes me wonder The audacity of dealers and manufacturers that put a residential refrigerator in a coach or trailer with two batteries.  Then even the new 12 volt furion refrigerator in my friend's new trailer required three batteries and 300 watts of solar at a sunny Beach camp out to sustain indefinitely.

[Tom Cherry]

2 hours ago, Gary_Curtis said:

I have found that the 110 system provides intermittent power when the generator is maxed out. I had three air conditioners and the fridge going at the same time and was trying to use a power tool plugged into one of the receptacles in the storage bay.  I turned off the Air conditioning units and 110 power was stable at the receptacle. 

I never did the math but my generator provides 10KW.  An air conditioner consumes about 1000 watts. A full size Refrigerator about 1000 watts. My power tool (10 in table saw) 1500W. When you add all that up it is only 5.5 KW but my generator may not be putting out 10KW. I have no way to actually measure its output.

 

Might ought to do the math and check the data plates.  Typically the 15KBTU AC's pull upwards of 16 - 17 amps.  That is almost 2000 watts. Your Res Refer has the amps (multiply by 120).  The FLA (Full Load Amps will be the startup....but then it drops off to about half). 

As to your 10 KW that is 5000 per side....  Look at the Circuit Breaker.  Is it (per the manual) a 2 pole 45 Amp breaker.  That is 10% less than your shore power (50 Amp) Pedestal.  Thus you only have half the power (total 10K) per leg or side. If you divide 5000 Watts by 45, that would be at a line voltage of 111 VAAC....so the 45 Amp protection is closer to 5,200 watts.  BUT....two things for you to consider....and you are probably doing this.

If you have NOT loaded up (maybe 50 - 75%) your genny and run it for an hour or so every 4 or so months and it sites for long storage times, your brushes get crappy and you will have voltage issues. 

The next is load balancing.....and from what you said....2 AC's on one side or line and then maybe throwing on a 1500 - 1800 Watt load....that will cause issues.

Your inverter, depending on the charging rate, will suck up maybe 1,500 watt as BULK...

Your Generator is probably working as designed and more than meets the advertised loads...PER SIDE....and when you overload one leg...strange things happen....maybe not enough to pop the CB, but it ain't doing it any good and doing the annual exercsing and load buildup to keep the brushes clean is a must.

[Newcsn]

This group is amazing! So grateful for all the feedback - I’m always learning more about these complex beasts (especially when it comes to the electrical side of things)!!! Here’s some follow up on questions asked/today’s experience:

• Original fridge - residential
• Never had it out to see if there’s 2 outlets behind 
• Fridge runs fine on generator & shore power
• Ours has a 10 KW generator
• Spoke w/ previous owner & he confirmed - the engine alternator/inverter will keep fridge running (plus a phone charger or six) - no need to run generator if that’s all the 110 we need.
• We do not attempt to run roof top units while driving w/o generator running - engine alternator/inverter can’t handle it. 
• Our experience last year (and PO’s) was, when we start the engine (w/o generator or shore power) it took the inverter a couple minutes to sort things out & then invert automatically to power the fridge.
• I attempted again this AM (engine only - no gen or shore power) & it failed to auto-invert.
• I pushed the “Inverter On/Off” button and it started to invert - fridge ran all day off inverter while engine running (no gen or shore power)
• As for putting the generator through its paces - we had all three heat pumps running last night. I’m hoping the knocked any of the cobwebs off the brushes! However, as stated above, my issue is not when the generator is running. 

I hope the feedback is helpful.

Now, just curious why it stopped auto-inverting when engine running (no gen or shore power)?

Thanks again - and we’ll see what happens tomorrow AM when we shove off for the next leg of our journey. 

[Tom Cherry]

9 minutes ago, Newcsn said:

This group is amazing! So grateful for all the feedback - I’m always learning more about these complex beasts (especially when it comes to the electrical side of things)!!! Here’s some follow up on questions asked/today’s experience:

• Original fridge - residential
• Never had it out to see if there’s 2 outlets behind 
• Fridge runs fine on generator & shore power
• Ours has a 10 KW generator
• Spoke w/ previous owner & he confirmed - the engine alternator/inverter will keep fridge running (plus a phone charger or six) - no need to run generator if that’s all the 110 we need.
• We do not attempt to run roof top units while driving w/o generator running - engine alternator/inverter can’t handle it. 
• Our experience last year (and PO’s) was, when we start the engine (w/o generator or shore power) it took the inverter a couple minutes to sort things out & then invert automatically to power the fridge.
• I attempted again this AM (engine only - no gen or shore power) & it failed to auto-invert.
• I pushed the “Inverter On/Off” button and it started to invert - fridge ran all day off inverter while engine running (no gen or shore power)
• As for putting the generator through its paces - we had all three heat pumps running last night. I’m hoping the knocked any of the cobwebs off the brushes! However, as stated above, my issue is not when the generator is running. 

I hope the feedback is helpful.

Now, just curious why it stopped auto-inverting when engine running (no gen or shore power)?

Thanks again - and we’ll see what happens tomorrow AM when we shove off for the next leg of our journey. 

OK....now that is beginning to make sense.  BUT, to correct a couple of your bullets...

You do NOT need to pull the Refrigerator OUT to see the outlets.  There is a lower compartment panel removable with twist locks and that is where the outlets are.

Your Fridge, if it was OEM, does NOT run off the Generator or Shore power.  It runs OFF of the Inverter....Don't remember what your inverter capacity is...but ALL RESIDENTAIL REFRIGERATORS had either a supplemental 1000 Watt Inverter (in addition to the standard 2000 Watt inverter) or there was a 2,800 Watt Inverter.  The inverter has an Automatic Transfer Switch inside it.  When you have Genny running or Shore plugged in, then the Inverter "sees" the voltage is there....matters NOT whether Shore or Genny.  THEN, (assuming and you probably DO have a Magnum Inverter), you MUST have a "decent functional" house bank.  Maybe will not run much for but a few minutes....but the Magnum HAS to start charging and see that the batteries are "taking a charge".  THEN, the Automatic Transfer Switch inside the Magnum pushes or allows the Genny or Shore Power to go to the various 115 circuits.  That is the Microwave and the outlets and the TV's and YES, a dedicated line for the Res Refer.  BUM BATTERIES....the Magnum ATS will NOT let you have any internal 120 VAC power.  YES...that seems confusing....but it how it works...

The Previous Owner PROBABLY mean that the Alternator is charging the House Bank as well as the Chassis Bank.  As LONG as you have any decent batteries (See above) then the Inverter is providing the 120 VAC to run it.  YES....the Alternator is a 200 A and the Inverter is built to "invert" enough power so that the Res Refer will be fine...

You have an ISSUE with the Inverter.  Probably not MAJOR....as in  "Needs a tech".  The inverter should instantaneously start inverting.  What you MAY have is one or both of the following.

The Inverter has a SETUP Button and you need to go through the various items and get it programmed properly.  If you call Magnum, a support tech will do that for you at NO CHARGE.  Tell him that the Inverter is balky.  Tell him that you want to turn OFF the Search Watts.  He will talk you through doing that...

The OTHER THING that needs to be done....NOW....is a SOFT RESET.  That is easy.  Located the WHITE inverter box in the bay.  unplug Shore and leave Genny OFF.  There is a POWER button on it.  Hold it in for maybe 30 seconds.  That is like rebooting a computer.  Then wait a few minutes....maybe 5 - 10.  Push the Power button.  That will turn ON the Inverter.  Go inside and look at the Magnum Remote.  There should be THREE green LED's on the LEFT side.  If there are NOT....then there MAY be an internal inverter error....and you have to do a HARD RESET...but Magnum will tell you. 

In my case....I had a BAD remote.  The Remote had a short or an intermittent in it.  It was BALKY and sometimes would not come on instantly (you never turn off the INVERTER OR CHARGER)...when it switched from Genny or Shore to "inverting" or running off the batteries.  I replaced mine. Four screws and a phone connector.  WORKS GREAT now....so a Balky Inverter does NEED some troubleshooting....

 You CANNOT run your roof top AC's from the Inverter.  Their power does NOT GO THROUGH IT.  When you need the Roof Tops (they cost less in diesel than the front HVAC to run), you ALWAYS have to start the Genny.  They will RUN....and BINGO....your Batteries are getting dual charged...as you drive....from both the Alternator on the Diesel and the Generator.  You need to understand this....

Assuming you ran the Genny last night and the three heat pumps....yes....that will clean the brushes.  

SO....to sum it up...

Do the Magnum Soft  Reset or ReStart....  Here is a link to read.....only leave it OFF for a few minutes.....then push and turn on the Invert on the WHITE BOX...

https://www.magnum-dimensions.com/soft-reset-instructions-magnum-energy-inverterchargers

Then look at your remote....all should be well.  Plug in to SHORE or start the Genny.  The remote will say "Inverting" when on Battery.  It should INSTANTEOUSLY switch to CHARGING when it senses the voltage (Genny or Shore).  If it is balky call Magnum and they will assist in the setup UP....BTW.....when you do that....there is a SHORE button.  Set the current or amperage to 30 AMPS.  YES....you may be on 50 amps.  BUT, there is a 30 Amp Circuit Breaker in the main AC panel. That is what you set the Inverter for....

[Ivylog]

6 hours ago, Gary_Curtis said:

. A full size Refrigerator about 1000 watts.

The 21 Whirlpool I installed draws 8 amps DC measured before inverter…96 watts. On average it uses 1.3KW measured with a KW meter… that works out to a 40% duty cycle and 16 cents/day to run. One good 12V battery will run it 20+ hours before needing to recharge at 50% SOC.

[TomV48]

Wow that's better than the measured results we had with the furion 12 volt

[Newcsn]

@Tom Cherry Wow, thanks for the incredibly detailed response - that helps immensely! Yep, Magnum 2800 inverter onboard! I did the soft reset & will provide follow up tomorrow. Thanks again!